Initial Commit

packages/api-stack/api/api-plugin-export/src/routes/problem-json/problem-json.ts

@@ -0,0 +1,72 @@
+import { SuaveplanError } from "@suaveplan/error";
+
+/** Standard RFC 7807 content-type. */
+export const PROBLEM_JSON_CONTENT_TYPE = "application/problem+json";
+
+/**
+ * Minimal structural Hono context surface relied on by
+ * {@link respondProblemJson}. Declared as an interface so the renderer
+ * does not couple to a specific Hono version.
+ */
+export interface HonoLike {
+    header(name: string, value: string): void;
+    body(data: string, status: number): Response;
+}
+
+/** RFC 7807 problem-details body. */
+export interface ProblemDetails {
+    readonly type: string;
+    readonly title: string;
+    readonly status: number;
+    readonly detail: string;
+    readonly code?: string;
+    readonly [key: string]: unknown;
+}
+
+/**
+ * Convert an arbitrary error into an RFC 7807 problem-details body and
+ * write it to the supplied Hono context. `SuaveplanError` subclasses
+ * surface their `code` and read `context.statusCode` for the HTTP code;
+ * plain `Error` and unknown throwables fall through to a generic
+ * `500 Internal Server Error`.
+ */
+export function respondProblemJson(c: HonoLike, err: unknown): Response {
+    const body = renderProblem(err);
+    c.header("content-type", PROBLEM_JSON_CONTENT_TYPE);
+    return c.body(JSON.stringify(body), body.status);
+}
+
+/**
+ * Pure render — kept separate from {@link respondProblemJson} so the
+ * shape can be asserted in tests that do not construct a Hono context.
+ */
+export function renderProblem(err: unknown): ProblemDetails {
+    if (err instanceof SuaveplanError) {
+        const ctx = err.context as { statusCode?: number } | undefined;
+        const status =
+            typeof ctx?.statusCode === "number" && ctx.statusCode >= 400
+                ? ctx.statusCode
+                : 500;
+        return {
+            type: `urn:suaveplan:error:${err.code.toLowerCase()}`,
+            title: err.name,
+            status,
+            detail: err.message,
+            code: err.code,
+        };
+    }
+    if (err instanceof Error) {
+        return {
+            type: "urn:suaveplan:error:internal",
+            title: err.name || "InternalError",
+            status: 500,
+            detail: err.message || "Internal Server Error",
+        };
+    }
+    return {
+        type: "urn:suaveplan:error:internal",
+        title: "InternalError",
+        status: 500,
+        detail: "Internal Server Error",
+    };
+}